1. Field of the Invention
As known in the art, any means of connecting fibers must resolve the alignment problem. When one considers that optical fibers have core diameters ranging from a few microns to a few tens of microns, and that an alignment error of as little as a diameter will result in a coupling loss of about 3 dB, the magnitude of the problem becomes apparent.
2. Description of the Pior Art
U.S. patent applications Ser. No. 762,312 filed Jan. 25, 1977, now U.S. Pat. No. 4,108,534 issued Aug. 22, 1978, has disclosed an apparatus for on-site connection of two optical fiber cables of the type having a central core with a periphery formed with regularly spaced grooves, each groove holding a fiber in the bottom thereof. The apparatus comprises two extension members, one for each cable to be connected, these extension members having a cylindrical shape and being formed with grooves having the same angular pitch as the fibers in the cables. After the fibers have been removed from the grooves of the end portions of the cables and the extension members have been secured to the cable cores, the fibers are bent back into the grooves of the extension members and bonded thereto.
Precise connecting is due to the fact that the grooved extension members are accurately calibrated members and that the fibers are passed to the bottom of the grooves before being bonded therein. Although this method of connecting fiber cables gives good results, it is not applicable to optical fiber ribbons.
U.S. Pat. No. 3,871,935 issued Mar. 18, 1975 disclosed a method of encapsulating and terminating an optical fiber ribbon comprising a plurality of optical fibers embedded in a common protective jacket including the steps of:
Dissolving the protective jacket along a portion of said ribbon thereby exposing the plurality of individual fibers; PA1 Placing the fibers thus exposed in a mold containing a positioning jig which aligns said fibers in a prefined manner relative to each other; PA1 adding an encapsulating material to said mold thereby encapsulating the fibers located therein in said predefined manner; PA1 and dividing said encapsulated fibers into two parts thereby exposing the transverse surfaces of said fibers. PA1 In this method, the fibers are guided by the positioning jig at a single point of their path in the plane of the jig and the angular connection error due to the obliquity of the fibers is not taken into consideration.